Re: [PATCH] bfq: silence lockdep for bfqd/ioc lock inversion

2021-04-15 Thread Jan Kara
On Wed 14-04-21 11:33:14, Khazhy Kumykov wrote: > On Wed, Apr 14, 2021 at 2:54 AM Jan Kara wrote: > > > > On Thu 18-03-21 23:00:15, Khazhismel Kumykov wrote: > > > lockdep warns of circular locking due to inversion between > > > bfq_insert_requests and bfq_exit_icq. If we end freeing a request whe

Re: [PATCH] bfq: silence lockdep for bfqd/ioc lock inversion

2021-04-14 Thread Khazhy Kumykov
On Wed, Apr 14, 2021 at 2:54 AM Jan Kara wrote: > > On Thu 18-03-21 23:00:15, Khazhismel Kumykov wrote: > > lockdep warns of circular locking due to inversion between > > bfq_insert_requests and bfq_exit_icq. If we end freeing a request when > > merging, we *may* grab an ioc->lock if that request

Re: [PATCH] bfq: silence lockdep for bfqd/ioc lock inversion

2021-04-14 Thread Jan Kara
On Thu 18-03-21 23:00:15, Khazhismel Kumykov wrote: > lockdep warns of circular locking due to inversion between > bfq_insert_requests and bfq_exit_icq. If we end freeing a request when > merging, we *may* grab an ioc->lock if that request is the last refcount > to that ioc. bfq_bio_merge also pote

[PATCH] bfq: silence lockdep for bfqd/ioc lock inversion

2021-03-18 Thread Khazhismel Kumykov
lockdep warns of circular locking due to inversion between bfq_insert_requests and bfq_exit_icq. If we end freeing a request when merging, we *may* grab an ioc->lock if that request is the last refcount to that ioc. bfq_bio_merge also potentially could have this ordering. bfq_exit_icq, conversely,